1. Field of the Invention
This invention relates to frequency sensitive switches and more specifically to frequency sensitive switches having a hysteresis characteristic.
2. Description of the Prior Art
Various kinds of frequency sensitive switches are known in the prior art. Many of these switches employ resonant means as a reference. In one variety of such switches, for instance, a mechanical member such as a resonant reed is used as a reference. Such switches, however, are temperature sensitive and therefore require additional means to compensate for such sensitivity if the switch is to be used in critical applications.
Still other prior art frequency sensitive switches employ a resonant circuit as a reference. Such circuits, however, are sensitive to input voltage fluctuations.
The circuit of the present invention overcomes the excessive temperature and voltage sensitivity characteristics of these prior art circuits.